Developing efficient neural network(NN)computing systems is crucial in the era of artificial intelligence(AI).Traditional von Neumann architectures have both the issues of"memory wall"and"power wall&quo...Developing efficient neural network(NN)computing systems is crucial in the era of artificial intelligence(AI).Traditional von Neumann architectures have both the issues of"memory wall"and"power wall",limiting the data transfer between memory and processing units[1,2].Compute-in-memory(CIM)technologies,particularly analogue CIM with memristor crossbars,are promising because of their high energy efficiency,computational parallelism,and integration density for NN computations[3].In practical applications,analogue CIM excels in tasks like speech recognition and image classification,revealing its unique advantages.For instance,it efficiently processes vast amounts of audio data in speech recognition,achieving high accuracy with minimal power consumption.In image classification,the high parallelism of analogue CIM significantly speeds up feature extraction and reduces processing time.With the boosting development of AI applications,the demands for computational accuracy and task complexity are rising continually.However,analogue CIM systems are limited in handling complex regression tasks with needs of precise floating-point(FP)calculations.They are primarily suited for the classification tasks with low data precision and a limited dynamic range[4].展开更多
This Special Topic of the Journal of Semiconductors(JOS)features expanded versions of key articles presented at the 2024 IEEE International Conference on Integrated Circuits Technologies and Applications(ICTA),which w...This Special Topic of the Journal of Semiconductors(JOS)features expanded versions of key articles presented at the 2024 IEEE International Conference on Integrated Circuits Technologies and Applications(ICTA),which was held in Hangzhou,Zhejiang,China,from October 25 to 27,2024.展开更多
Infrared and terahertz waves constitute pivotal bands within the electromagnetic spectrum,distinguished by their robust penetration capabilities and non-ionizing nature.These wavebands offer the potential for achievin...Infrared and terahertz waves constitute pivotal bands within the electromagnetic spectrum,distinguished by their robust penetration capabilities and non-ionizing nature.These wavebands offer the potential for achieving high-resolution and non-destructive detection methodologies,thereby possessing considerable research significance across diverse domains including communication technologies,biomedical applications,and security screening systems.Two-dimensional materials,owing to their distinctive optoelectronic attributes,have found widespread application in photodetection endeavors.Nonetheless,their efficacy diminishes when tasked with detecting lower photon energies.Furthermore,as the landscape of device integration evolves,two-dimensional materials struggle to align with the stringent demands for device superior performance.Topological materials,with their topologically protected electronic states and non-trivial topological invariants,exhibit quantum anomalous Hall effects and ultra-high carrier mobility,providing a new approach for seeking photosensitive materials for infrared and terahertz photodetectors.This article introduces various types of topological materials and their properties,followed by an explanation of the detection mechanism and performance parameters of photodetectors.Finally,it summarizes the current research status of near-infrared to far-infrared photodetectors and terahertz photodetectors based on topological materials,discussing the challenges faced and future prospects in their development.展开更多
A new theoretical method to study super-multiperiod superlattices has been developed.The method combines the precision of the 8-band kp-method with the flexibility of the shooting method and the Monte Carlo approach.T...A new theoretical method to study super-multiperiod superlattices has been developed.The method combines the precision of the 8-band kp-method with the flexibility of the shooting method and the Monte Carlo approach.This method was applied to examine the finest quality samples of super-multiperiod Al_(0.3)Ga_(0.7)As/GaAs superlattices grown by molecular beam epitaxy.The express photoreflectance spectroscopy method was utilized to validate the proposed theoretical method.For the first time,the accurate theoretical analysis of the energy band diagram of super-multiperiod superlattices with experimental verification has been conducted.The proposed approach highly accurately determines transition peak positions and enables the calculation of the energy band diagram,transition energies,relaxation rates,and gain estimation.It has achieved a remarkably low 5%error compared to the commonly used method,which typically results in a 25%error,and allowed to recover the superlattice parameters.The retrieved intrinsic parameters of the samples aligned with XRD data and growth parameters.The proposed method also accurately predicted the escape of the second energy level for quantum well thicknesses less than 5 nm,as was observed in photoreflectance experiments.The new designs of THz light-emitting devices operating at room temperature were suggested by the developed method.展开更多
Simulating the human olfactory nervous system is one of the key issues in the field of neuromorphic computing.Olfac-tory neurons interact with gas molecules,transmitting and storing odor information to the olfactory c...Simulating the human olfactory nervous system is one of the key issues in the field of neuromorphic computing.Olfac-tory neurons interact with gas molecules,transmitting and storing odor information to the olfactory center of the brain.In order to emulate the complex functionalities of olfactory neurons,this study presents a flexible olfactory synapse transistor(OST)based on pentacene/C8-BTBT organic heterojunction.By modulating the interface between the energy bands of the organic semiconductor layers,this device demonstrates high sensitivity(ppb level)and memory function for NH3 sensing.Typi-cal synaptic behaviors triggered by NH_(3) pulses have been successfully demonstrated,such as inhibitory postsynaptic currents(IPSC),paired-pulse depression(PPD),long-term potentiation/depression(LTP/LTD),and transition from short-term depression(STD)to long-term depression(LTD).Furthermore,this device maintains stable olfactory synaptic functions even under differ-ent bending conditions,which can present new insights and possibilities for flexible synaptic systems and bio-inspired elec-tronic products.展开更多
In recent years,organic solar cells(OSCs)have garnered significant attention due to their distinctive attributes,such as flexibility,lightweight,and solution processing,which position them as alternatives for next-gen...In recent years,organic solar cells(OSCs)have garnered significant attention due to their distinctive attributes,such as flexibility,lightweight,and solution processing,which position them as alternatives for next-generation solar technologies[1−5].Thanks to breakthroughs in materials development,the power conversion efficiency(PCE)for single-junction OSCs has already surpassed 19%[6−13].The development of photoactive materials is pivotal in enhancing the PCEs,and several reviews have provided insights into materials design[14−18].Herein,we highlight single-junction OSCs based on D18 and its derivatives[19,20].展开更多
The stability of organic solar cells(OSCs)remains a major concern for their ultimate industrialization due to the photo,oxygen,and water susceptibility of organic photoactive materials.Usually,antioxidant additives ar...The stability of organic solar cells(OSCs)remains a major concern for their ultimate industrialization due to the photo,oxygen,and water susceptibility of organic photoactive materials.Usually,antioxidant additives are blended as radical scavengers into the active layer.However,it will induce the intrinsic morphology instability and adversely affect the efficiency and long-term stability.Herein,the antioxidant dibutylhydroxytoluene(BHT)group has been covalently linked onto the side chain of benzothiadiazole(BT)unit,and a series of ternary copolymers D18-Cl-BTBHTx(x=0,0.05,0.1,0.2)with varied ratio of BHT-containing side chains have been synthesized.It was found that the introduction of BHT side chains would have a negligible effect on the photophysical properties and electronic levels,and the D18-Cl-BTBHT0.05:Y6-based OSC achieved the highest power conversion efficiency(PCE)of 17.6%,which is higher than those based active layer blended with BHT additives.More importantly,the unencapsulated device based on D18-Cl-BTBHTx(x=0.05,0.1,0.2)retained approximately 50%of the initial PCE over 30 hours operation under ambient conditions,significantly outperforming the control device based on D18-Cl(90%degradation in PCE after 30 h).This work provides a new structural design strategy of copolymers for OSCs with simultaneously improved efficiency and stability.展开更多
Microcantilever is one of the most popular miniaturized structures in micro-electromechanical systems(MEMS).Sensors based on microcantilever are ideal for biochemical detection,since they have high sensitivity,high th...Microcantilever is one of the most popular miniaturized structures in micro-electromechanical systems(MEMS).Sensors based on microcantilever are ideal for biochemical detection,since they have high sensitivity,high throughput,good specification,fast response,thus have attracted extensive attentions.A number of devices that are based on static deflections or shifts of resonant frequency of the cantilevers responding to analyte attachment have been demonstrated.This review comprehensively presents state of art of microcantilever sensors working in gaseous and aqueous environments and highlights the challenges and opportunities of microcantilever biochemical sensors.展开更多
Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron s...Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron sputtering. The films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet visible spectroscopy, and the effect of annealing atmosphere on the properties of films was studied. The Ga_(2)O_(3) films changed from amorphous to β-Ga_(2)O_(3) after annealing at 900 °C. The films were composed of micro crystalline particles with a diameter of about 5–20 nm.The β-Ga_(2)O_(3) had high transmittance for wavelengths above 300 nm, and obvious absorption for solar-blind signals at 200–280 nm.The metal semiconductor metal type solar-blind detectors were prepared. The detector based on Sn-doped β-Ga_(2)O_(3) thin film annealed in N_2 has the best response performance to 254 nm light. The photo-current is 10 μA at 20 V, the dark-current is 5.76 pA,the photo dark current ratio is 1.7 × 10~6, the response rate is 12.47 A/W, the external quantum efficiency is 6.09 × 10~3%, the specific detection rate is 2.61 × 10~(12) Jones, the response time and recovery time are 378 and 90 ms, respectively.展开更多
Organic solar cells(OSCs)have made significant progress due to the fast advances in nonfullerene acceptors(NFAs)since 2015^([1−7]).The power conversion efficiency(PCE)for small-area single-junction OSCs is around 19%w...Organic solar cells(OSCs)have made significant progress due to the fast advances in nonfullerene acceptors(NFAs)since 2015^([1−7]).The power conversion efficiency(PCE)for small-area single-junction OSCs is around 19%with an active area<0.1 cm^(2[8−11]).Scalability is a key factor in developing this technology.When scaling lab cells to large-area modules,the device performance might drop.Brabec et al.proposed a stage–gate process for OSCs from R&D effort to commercialization,which includes materials development,processing,prototyping,pilot process and upscaling[12].展开更多
Two-dimensional(2D)materials have attracted considerable interest thanks to their unique electronic/physical-chemical characteristics and their potential for use in a large variety of sensing applications.However,few-...Two-dimensional(2D)materials have attracted considerable interest thanks to their unique electronic/physical-chemical characteristics and their potential for use in a large variety of sensing applications.However,few-layered nanosheets tend to agglomerate owing to van der Waals forces,which obstruct internal nanoscale transport channels,resulting in low electrochemical activity and restricting their use for sensing purposes.Here,a hybrid MXene/rGO aerogel with a three-dimensional(3D)interlocked network was fabricated via a freeze-drying method.The porous MXene/rGO aerogel has a lightweight and hierarchical porous architecture,which can be compressed and expanded several times without breaking.Additionally,a flexible pressure sensor that uses the aerogel as the sensitive layer has a wide response range of approximately 0-40 kPa and a considerable response within this range,averaging approximately 61.49 kPa^(-1).The excellent sensing performance endows it with a broad range of applications,including human-computer interfaces and human health monitoring.展开更多
Al-rich nitride,as one of the most important ultra-wide band-gap(UWBG)semiconductors,currently plays the key role of deep ultraviolet(DUV)optoelectronics and potentially possesses the advantages of the huge global inv...Al-rich nitride,as one of the most important ultra-wide band-gap(UWBG)semiconductors,currently plays the key role of deep ultraviolet(DUV)optoelectronics and potentially possesses the advantages of the huge global investment in the manufacturing infrastructure associated with In Ga N material that has become the second most important semiconductor material after Si in the late 2010s[1,2].展开更多
In this paper,the reliability of sense-switch p-channel flash is evaluated extensively.The endurance result indicates that the p-channel flash could be programmed and erased for more than 10000 cycles;the room tempera...In this paper,the reliability of sense-switch p-channel flash is evaluated extensively.The endurance result indicates that the p-channel flash could be programmed and erased for more than 10000 cycles;the room temperature read stress shows negligible influence on the p-channel flash cell;high temperature data retention at 150℃ is extrapolated to be about 5 years and 53 years corresponding to 30% and 40% degradation in the drive current,respectively.Moreover,the electrical parameters of the p-channel flash at different operation temperature are found to be less affected.All the results above indicate that the sense-switch p-channel flash is suitable to be used as the configuration cell in flash-based FPGA.展开更多
Band offset in semiconductors is a fundamental physical quantity that determines the performance of optoelectronic devices.However,the current method of calculating band offset is difficult to apply directly to the la...Band offset in semiconductors is a fundamental physical quantity that determines the performance of optoelectronic devices.However,the current method of calculating band offset is difficult to apply directly to the large-lattice-mismatched and heterovalent semiconductors because of the existing electric field and large strain at the interfaces.Here,we proposed a modified method to calculate band offsets for such systems,in which the core energy level shifts caused by heterovalent effects and lattice mismatch are estimated by interface reconstruction and the insertion of unidirectional strain structures as transitions,respectively.Taking the Si and III-V systems as examples,the results have the same accuracy as what is a widely used method for small-lattice-mismatched systems,and are much closer to the experimental values for the large-lattice-mismatched and heterovalent systems.Furthermore,by systematically studying the heterojunctions of Si and III-V semiconductors along different directions,it is found that the band offsets of Si/InAs and Si/InSb systems in[100],[110]and[111]directions belong to the type I,and could be beneficial for silicon-based luminescence performance.Our study offers a more reliable and direct method for calculating band offsets of large-lattice-mismatched and heterovalent semiconductors,and could provide theoretical support for the design of the high-performance silicon-based light sources.展开更多
Flexible batteries are key component of wearable electronic devices.Based on the requirements of medical and primary safety of wearable energy storage devices,rechargeable aqueous zinc ion batteries(ZIBs)are promising...Flexible batteries are key component of wearable electronic devices.Based on the requirements of medical and primary safety of wearable energy storage devices,rechargeable aqueous zinc ion batteries(ZIBs)are promising portable candidates in virtue of its intrinsic safety,abundant storage and low cost.However,many inherent challenges have greatly hindered the development in flexible Zn-based energy storage devices,such as rigid current collector and/or metal anode,easily detached cathode materials and a relatively narrow voltage window of flexible electrolyte.Thus,overcoming these challenges and further developing flexible ZIBs are inevitable and imperative.This review summarizes the most advanced progress in designs and discusses of flexible electrode,electrolyte and the practical application of flexible ZIBs in different environments.We also exhibit the heart of the matter that current flexible ZIBs faces.Finally,some prospective approaches are proposed to address these key issues and point out the direction for the future development of flexible ZIBs.展开更多
Recently,C568 has emerged as a new carbon allotrope,which shows semiconducting properties with a band gap around 1 eV and has attracted much attention.In this work,the external strain effects on the electronic propert...Recently,C568 has emerged as a new carbon allotrope,which shows semiconducting properties with a band gap around 1 eV and has attracted much attention.In this work,the external strain effects on the electronic properties of C568 have been studied theoretically through first-principle calculations.The numerical results show that while in-plane uniaxial and biaxial strains both reduces the band gap of C568 in case of tensile strain,their effects are quite different in the case of compressive strain.With increasing compressive uniaxial strain,the band gap of C568 first increases,and then dramatically decreases.In contrast,the application of compressive biaxial strain up to -10% only leads to a slight increase of band gap.Moreover,an indirect-todirect gap transition can be realized under both types of compressive strain.The results also show that the optical anisotropy of C568 can be induced under uniaxial strain,while biaxial strain does not cause such an effect.These results indicate good strain tunability of the band structure of C568,which could be helpful for the design and optimization of C568-based nanodevices.展开更多
A large number of two-dimensional(2D)monoelemental materials with huge application potentials have been developed,since graphene was reported as a monoelemental material with unique properties.As cousins of graphene,2...A large number of two-dimensional(2D)monoelemental materials with huge application potentials have been developed,since graphene was reported as a monoelemental material with unique properties.As cousins of graphene,2D group-V elemental monolayers have gained tremendous interest due to their electronic properties with significant fundamental bandgap.In this review,we extensively summarize the latest theoretical and experimental progress in group-V monoelemental materials,including the latest fabrication methods,the properties and potential applications of these 2D monoelementals.We also give a perspective of the challenges and opportunities of 2D monoelemental group-V monolayer materials and related functional nanodevices.展开更多
Type-Ⅱsuperlattice(T2SL)materials are the key element for infrared(IR)detectors.However,it is well known that the characteristics of the detectors with the T2SL layer are greatly affected by the strain developed duri...Type-Ⅱsuperlattice(T2SL)materials are the key element for infrared(IR)detectors.However,it is well known that the characteristics of the detectors with the T2SL layer are greatly affected by the strain developed during the growth process,which determines the performance of IR detectors.Therefore,great efforts have been made to properly control the strain effect and develop relevant analysis methods to evaluate the strain-induced dark current characteristics.In this work,we report the strain-induced dark current characteristics in InAs/GaSb T2SL MWIR photodetector.The overall strain of InAs/GaSb T2SL layer was analyzed by both high-resolution X-ray diffraction(HRXRD)and the dark current measured from the absorber layer at the elevated temperatures(≥110 K),where the major leakage current component is originated from the reduced minority carrier lifetime in the absorber layer.Our findings indicate that minority carrier lifetime increases as the tensile strain on the InAs/GaSb T2SL is more compensated by the compressive strain through‘InSb-like’interface,which reduces the dark current density of the device.Specifically,tensile strain compensated devices exhibited the dark current density of less than 2×10^-5 A/cm^2 at 120 K,which is more than one order of magnitude lower value compared to that of the device without tensile strain relaxation.展开更多
Au80Sn20 alloy is a widely used solder for laser diode packaging.In this paper,the thermal resistance of Ga N-based blue laser diodes packaged in TO56 cans were measured by the forward voltage method.The microstructur...Au80Sn20 alloy is a widely used solder for laser diode packaging.In this paper,the thermal resistance of Ga N-based blue laser diodes packaged in TO56 cans were measured by the forward voltage method.The microstructures of Au80Sn20 solder were then investigated to understand the reason for the difference in thermal resistance.It was found that the microstructure with a higher content of Au-rich phase in the center of the solder and a lower content of(Au,Ni)Sn phase at the interface of the solder/heat sink resulted in lower thermal resistance.This is attributed to the lower thermal resistance of Au-rich phase and higher thermal resistance of(Au,Ni)Sn phase.展开更多
High computational energy-efficiency and rapid real-timeresponse are the major concerns for applications of artificial intelligencein low-power mobile and Internet of Things deviceswith limited storage capacity. Due t...High computational energy-efficiency and rapid real-timeresponse are the major concerns for applications of artificial intelligencein low-power mobile and Internet of Things deviceswith limited storage capacity. Due to the outstanding superiorityof less memory requirement, low computation overheadand negligible accuracy degradation, deep neural networkswith binary/ternary weights (BTNNs) have been widely adoptedto replace traditional full-precision neural networks.展开更多
文摘Developing efficient neural network(NN)computing systems is crucial in the era of artificial intelligence(AI).Traditional von Neumann architectures have both the issues of"memory wall"and"power wall",limiting the data transfer between memory and processing units[1,2].Compute-in-memory(CIM)technologies,particularly analogue CIM with memristor crossbars,are promising because of their high energy efficiency,computational parallelism,and integration density for NN computations[3].In practical applications,analogue CIM excels in tasks like speech recognition and image classification,revealing its unique advantages.For instance,it efficiently processes vast amounts of audio data in speech recognition,achieving high accuracy with minimal power consumption.In image classification,the high parallelism of analogue CIM significantly speeds up feature extraction and reduces processing time.With the boosting development of AI applications,the demands for computational accuracy and task complexity are rising continually.However,analogue CIM systems are limited in handling complex regression tasks with needs of precise floating-point(FP)calculations.They are primarily suited for the classification tasks with low data precision and a limited dynamic range[4].
文摘This Special Topic of the Journal of Semiconductors(JOS)features expanded versions of key articles presented at the 2024 IEEE International Conference on Integrated Circuits Technologies and Applications(ICTA),which was held in Hangzhou,Zhejiang,China,from October 25 to 27,2024.
基金supported by the National Key R&D Program of China(Grant No.2024YFA1211300)Outstanding Youth Foundation of NSFC(Grant No.62322515)+5 种基金Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Shanghai Natural Science Foundation Project(Grant No.24ZR1493100)International Partnership Program of Chinese Academy of Sciences(Grant No.112GJHZ2024039FN)the support from Analytical Instrumentation Center(#SPST-AIC10112914)Soft Matter Nanofab(#SPST-SMN180827)Quantum Device Lab,Shanghai Tech University。
文摘Infrared and terahertz waves constitute pivotal bands within the electromagnetic spectrum,distinguished by their robust penetration capabilities and non-ionizing nature.These wavebands offer the potential for achieving high-resolution and non-destructive detection methodologies,thereby possessing considerable research significance across diverse domains including communication technologies,biomedical applications,and security screening systems.Two-dimensional materials,owing to their distinctive optoelectronic attributes,have found widespread application in photodetection endeavors.Nonetheless,their efficacy diminishes when tasked with detecting lower photon energies.Furthermore,as the landscape of device integration evolves,two-dimensional materials struggle to align with the stringent demands for device superior performance.Topological materials,with their topologically protected electronic states and non-trivial topological invariants,exhibit quantum anomalous Hall effects and ultra-high carrier mobility,providing a new approach for seeking photosensitive materials for infrared and terahertz photodetectors.This article introduces various types of topological materials and their properties,followed by an explanation of the detection mechanism and performance parameters of photodetectors.Finally,it summarizes the current research status of near-infrared to far-infrared photodetectors and terahertz photodetectors based on topological materials,discussing the challenges faced and future prospects in their development.
基金The work was supported by the Ministry of Education and Science of the Russian Federation in the framework of experimental research(Nos.075-01438-22-06 and FSEE-2022-0018)the Russian Science Foundation in theoretical research(No.RSF 23-29-00216).
文摘A new theoretical method to study super-multiperiod superlattices has been developed.The method combines the precision of the 8-band kp-method with the flexibility of the shooting method and the Monte Carlo approach.This method was applied to examine the finest quality samples of super-multiperiod Al_(0.3)Ga_(0.7)As/GaAs superlattices grown by molecular beam epitaxy.The express photoreflectance spectroscopy method was utilized to validate the proposed theoretical method.For the first time,the accurate theoretical analysis of the energy band diagram of super-multiperiod superlattices with experimental verification has been conducted.The proposed approach highly accurately determines transition peak positions and enables the calculation of the energy band diagram,transition energies,relaxation rates,and gain estimation.It has achieved a remarkably low 5%error compared to the commonly used method,which typically results in a 25%error,and allowed to recover the superlattice parameters.The retrieved intrinsic parameters of the samples aligned with XRD data and growth parameters.The proposed method also accurately predicted the escape of the second energy level for quantum well thicknesses less than 5 nm,as was observed in photoreflectance experiments.The new designs of THz light-emitting devices operating at room temperature were suggested by the developed method.
基金supported by the National Key Research and Development Program of China (2021YFA120260)the NSFC (92064009,22175042,12474071)+3 种基金the Science and Technology Commission of Shanghai Municipality (22501100900)Natural Science Foundation of Shandong Province (ZR2024YQ051)the China Postdoctoral Science Foundation (2022TQ0068,2023M740644)the Shanghai Sailing Program (23YF1402200,23YF1402400).
文摘Simulating the human olfactory nervous system is one of the key issues in the field of neuromorphic computing.Olfac-tory neurons interact with gas molecules,transmitting and storing odor information to the olfactory center of the brain.In order to emulate the complex functionalities of olfactory neurons,this study presents a flexible olfactory synapse transistor(OST)based on pentacene/C8-BTBT organic heterojunction.By modulating the interface between the energy bands of the organic semiconductor layers,this device demonstrates high sensitivity(ppb level)and memory function for NH3 sensing.Typi-cal synaptic behaviors triggered by NH_(3) pulses have been successfully demonstrated,such as inhibitory postsynaptic currents(IPSC),paired-pulse depression(PPD),long-term potentiation/depression(LTP/LTD),and transition from short-term depression(STD)to long-term depression(LTD).Furthermore,this device maintains stable olfactory synaptic functions even under differ-ent bending conditions,which can present new insights and possibilities for flexible synaptic systems and bio-inspired elec-tronic products.
基金J.Yang thanks the National Key Research and Development Program of China(2022YFB3803300)the National Natural Science Foundation of China(U23A20138 and 52173192)+1 种基金L.Ding thanks the National Key Research and Development Program of China(2022YFB3803300,2023YFE0116800)Beijing Natural Science Foundation(IS23037).
文摘In recent years,organic solar cells(OSCs)have garnered significant attention due to their distinctive attributes,such as flexibility,lightweight,and solution processing,which position them as alternatives for next-generation solar technologies[1−5].Thanks to breakthroughs in materials development,the power conversion efficiency(PCE)for single-junction OSCs has already surpassed 19%[6−13].The development of photoactive materials is pivotal in enhancing the PCEs,and several reviews have provided insights into materials design[14−18].Herein,we highlight single-junction OSCs based on D18 and its derivatives[19,20].
基金This work was financially supported by National Key Research and Development Program of China(No.2019YFA0705900)funded by MOSTthe Basic and Applied Basic Research Major Program of Guangdong Province(No.2019B030302007)+1 种基金the National Natural Science Foundation of China(No.U21A6002)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(No.2019B121205002).
文摘The stability of organic solar cells(OSCs)remains a major concern for their ultimate industrialization due to the photo,oxygen,and water susceptibility of organic photoactive materials.Usually,antioxidant additives are blended as radical scavengers into the active layer.However,it will induce the intrinsic morphology instability and adversely affect the efficiency and long-term stability.Herein,the antioxidant dibutylhydroxytoluene(BHT)group has been covalently linked onto the side chain of benzothiadiazole(BT)unit,and a series of ternary copolymers D18-Cl-BTBHTx(x=0,0.05,0.1,0.2)with varied ratio of BHT-containing side chains have been synthesized.It was found that the introduction of BHT side chains would have a negligible effect on the photophysical properties and electronic levels,and the D18-Cl-BTBHT0.05:Y6-based OSC achieved the highest power conversion efficiency(PCE)of 17.6%,which is higher than those based active layer blended with BHT additives.More importantly,the unencapsulated device based on D18-Cl-BTBHTx(x=0.05,0.1,0.2)retained approximately 50%of the initial PCE over 30 hours operation under ambient conditions,significantly outperforming the control device based on D18-Cl(90%degradation in PCE after 30 h).This work provides a new structural design strategy of copolymers for OSCs with simultaneously improved efficiency and stability.
基金supported by National Science Foundation of China(61804107,61804150)National Key Research and Development Program of China(2022YFF0706102)Tianjin Municipal Science and Technology Bureau(20JCQNJC00180).
文摘Microcantilever is one of the most popular miniaturized structures in micro-electromechanical systems(MEMS).Sensors based on microcantilever are ideal for biochemical detection,since they have high sensitivity,high throughput,good specification,fast response,thus have attracted extensive attentions.A number of devices that are based on static deflections or shifts of resonant frequency of the cantilevers responding to analyte attachment have been demonstrated.This review comprehensively presents state of art of microcantilever sensors working in gaseous and aqueous environments and highlights the challenges and opportunities of microcantilever biochemical sensors.
基金supported by the National Natural Science Foundation of China (Grant No. 62204203)the Shaanxi Natural Science Basic Research Program (Grant No. 2022JQ-701)。
文摘Sn doping is an effective way to improve the response rate of Ga_(2)O_(3) film based solar-blind detectors. In this paper,Sn-doped Ga_(2)O_(3) films were prepared on a sapphire substrate by radio frequency magnetron sputtering. The films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet visible spectroscopy, and the effect of annealing atmosphere on the properties of films was studied. The Ga_(2)O_(3) films changed from amorphous to β-Ga_(2)O_(3) after annealing at 900 °C. The films were composed of micro crystalline particles with a diameter of about 5–20 nm.The β-Ga_(2)O_(3) had high transmittance for wavelengths above 300 nm, and obvious absorption for solar-blind signals at 200–280 nm.The metal semiconductor metal type solar-blind detectors were prepared. The detector based on Sn-doped β-Ga_(2)O_(3) thin film annealed in N_2 has the best response performance to 254 nm light. The photo-current is 10 μA at 20 V, the dark-current is 5.76 pA,the photo dark current ratio is 1.7 × 10~6, the response rate is 12.47 A/W, the external quantum efficiency is 6.09 × 10~3%, the specific detection rate is 2.61 × 10~(12) Jones, the response time and recovery time are 378 and 90 ms, respectively.
基金X.Du thanks National Natural Science Foundation of China(52103222)Natural Science Foundation of Shandong Province(ZR2021QA009)+3 种基金Taishan Scholar Foundation of Shandong Province(tsqn202103016)Qilu Young Scholar Program of Shandong University.L.Ding thanks the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51922032 and 21961160720)the open research fund of Songshan Lake Materials Laboratory(2021SLABFK02)for financial support.
文摘Organic solar cells(OSCs)have made significant progress due to the fast advances in nonfullerene acceptors(NFAs)since 2015^([1−7]).The power conversion efficiency(PCE)for small-area single-junction OSCs is around 19%with an active area<0.1 cm^(2[8−11]).Scalability is a key factor in developing this technology.When scaling lab cells to large-area modules,the device performance might drop.Brabec et al.proposed a stage–gate process for OSCs from R&D effort to commercialization,which includes materials development,processing,prototyping,pilot process and upscaling[12].
基金financial support from the National Natural Science Foundation of China(NSFC Grant No.61625404,61888102,62174152)Young Elite Scientists Sponsorship Program by CAST(2018QNRC001)+1 种基金the Strategic Priority Program of the Chinese Academy of Sciences,Grant No XDA16021100the Science and Technology Development Plan of Jilin Province(20210101168JC).
文摘Two-dimensional(2D)materials have attracted considerable interest thanks to their unique electronic/physical-chemical characteristics and their potential for use in a large variety of sensing applications.However,few-layered nanosheets tend to agglomerate owing to van der Waals forces,which obstruct internal nanoscale transport channels,resulting in low electrochemical activity and restricting their use for sensing purposes.Here,a hybrid MXene/rGO aerogel with a three-dimensional(3D)interlocked network was fabricated via a freeze-drying method.The porous MXene/rGO aerogel has a lightweight and hierarchical porous architecture,which can be compressed and expanded several times without breaking.Additionally,a flexible pressure sensor that uses the aerogel as the sensitive layer has a wide response range of approximately 0-40 kPa and a considerable response within this range,averaging approximately 61.49 kPa^(-1).The excellent sensing performance endows it with a broad range of applications,including human-computer interfaces and human health monitoring.
文摘Al-rich nitride,as one of the most important ultra-wide band-gap(UWBG)semiconductors,currently plays the key role of deep ultraviolet(DUV)optoelectronics and potentially possesses the advantages of the huge global investment in the manufacturing infrastructure associated with In Ga N material that has become the second most important semiconductor material after Si in the late 2010s[1,2].
文摘In this paper,the reliability of sense-switch p-channel flash is evaluated extensively.The endurance result indicates that the p-channel flash could be programmed and erased for more than 10000 cycles;the room temperature read stress shows negligible influence on the p-channel flash cell;high temperature data retention at 150℃ is extrapolated to be about 5 years and 53 years corresponding to 30% and 40% degradation in the drive current,respectively.Moreover,the electrical parameters of the p-channel flash at different operation temperature are found to be less affected.All the results above indicate that the sense-switch p-channel flash is suitable to be used as the configuration cell in flash-based FPGA.
基金This work was supported by the National Key Research and Development Program of China(Grant No.2018YFB2200100)the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB22)+1 种基金the National Natural Science Foundation of China(Grant No.118764347,11614003,11804333)H.X.D.was also supported by the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2017154).
文摘Band offset in semiconductors is a fundamental physical quantity that determines the performance of optoelectronic devices.However,the current method of calculating band offset is difficult to apply directly to the large-lattice-mismatched and heterovalent semiconductors because of the existing electric field and large strain at the interfaces.Here,we proposed a modified method to calculate band offsets for such systems,in which the core energy level shifts caused by heterovalent effects and lattice mismatch are estimated by interface reconstruction and the insertion of unidirectional strain structures as transitions,respectively.Taking the Si and III-V systems as examples,the results have the same accuracy as what is a widely used method for small-lattice-mismatched systems,and are much closer to the experimental values for the large-lattice-mismatched and heterovalent systems.Furthermore,by systematically studying the heterojunctions of Si and III-V semiconductors along different directions,it is found that the band offsets of Si/InAs and Si/InSb systems in[100],[110]and[111]directions belong to the type I,and could be beneficial for silicon-based luminescence performance.Our study offers a more reliable and direct method for calculating band offsets of large-lattice-mismatched and heterovalent semiconductors,and could provide theoretical support for the design of the high-performance silicon-based light sources.
基金the National Key R&D Program of China under Project 2019YFA0705104.
文摘Flexible batteries are key component of wearable electronic devices.Based on the requirements of medical and primary safety of wearable energy storage devices,rechargeable aqueous zinc ion batteries(ZIBs)are promising portable candidates in virtue of its intrinsic safety,abundant storage and low cost.However,many inherent challenges have greatly hindered the development in flexible Zn-based energy storage devices,such as rigid current collector and/or metal anode,easily detached cathode materials and a relatively narrow voltage window of flexible electrolyte.Thus,overcoming these challenges and further developing flexible ZIBs are inevitable and imperative.This review summarizes the most advanced progress in designs and discusses of flexible electrode,electrolyte and the practical application of flexible ZIBs in different environments.We also exhibit the heart of the matter that current flexible ZIBs faces.Finally,some prospective approaches are proposed to address these key issues and point out the direction for the future development of flexible ZIBs.
文摘Recently,C568 has emerged as a new carbon allotrope,which shows semiconducting properties with a band gap around 1 eV and has attracted much attention.In this work,the external strain effects on the electronic properties of C568 have been studied theoretically through first-principle calculations.The numerical results show that while in-plane uniaxial and biaxial strains both reduces the band gap of C568 in case of tensile strain,their effects are quite different in the case of compressive strain.With increasing compressive uniaxial strain,the band gap of C568 first increases,and then dramatically decreases.In contrast,the application of compressive biaxial strain up to -10% only leads to a slight increase of band gap.Moreover,an indirect-todirect gap transition can be realized under both types of compressive strain.The results also show that the optical anisotropy of C568 can be induced under uniaxial strain,while biaxial strain does not cause such an effect.These results indicate good strain tunability of the band structure of C568,which could be helpful for the design and optimization of C568-based nanodevices.
基金the financial supporting from National Natural Science Foundation of China(Nos.61971035,61901038,61725107)Beijing Natural Science Foundation(Nos.Z190006,4192054)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDB30000000)Beijing Institute of Technology Research Fund Program for Young Scholars(3050011181814).
文摘A large number of two-dimensional(2D)monoelemental materials with huge application potentials have been developed,since graphene was reported as a monoelemental material with unique properties.As cousins of graphene,2D group-V elemental monolayers have gained tremendous interest due to their electronic properties with significant fundamental bandgap.In this review,we extensively summarize the latest theoretical and experimental progress in group-V monoelemental materials,including the latest fabrication methods,the properties and potential applications of these 2D monoelementals.We also give a perspective of the challenges and opportunities of 2D monoelemental group-V monolayer materials and related functional nanodevices.
基金supported by the research fund of Chungnam National University
文摘Type-Ⅱsuperlattice(T2SL)materials are the key element for infrared(IR)detectors.However,it is well known that the characteristics of the detectors with the T2SL layer are greatly affected by the strain developed during the growth process,which determines the performance of IR detectors.Therefore,great efforts have been made to properly control the strain effect and develop relevant analysis methods to evaluate the strain-induced dark current characteristics.In this work,we report the strain-induced dark current characteristics in InAs/GaSb T2SL MWIR photodetector.The overall strain of InAs/GaSb T2SL layer was analyzed by both high-resolution X-ray diffraction(HRXRD)and the dark current measured from the absorber layer at the elevated temperatures(≥110 K),where the major leakage current component is originated from the reduced minority carrier lifetime in the absorber layer.Our findings indicate that minority carrier lifetime increases as the tensile strain on the InAs/GaSb T2SL is more compensated by the compressive strain through‘InSb-like’interface,which reduces the dark current density of the device.Specifically,tensile strain compensated devices exhibited the dark current density of less than 2×10^-5 A/cm^2 at 120 K,which is more than one order of magnitude lower value compared to that of the device without tensile strain relaxation.
基金supported by the National Key Research and Development Program of China(Grant Nos.2016YFB0401803,2017YFE0131500,2017YFB0405000)National Natural Science Foundation of China(Grant Nos.61834008,61574160,61804164,and 61704184)+1 种基金Natural Science Foundation of Jiangsu province(BK20180254)China Postdoctoral Science Foundation(2018M630619)。
文摘Au80Sn20 alloy is a widely used solder for laser diode packaging.In this paper,the thermal resistance of Ga N-based blue laser diodes packaged in TO56 cans were measured by the forward voltage method.The microstructures of Au80Sn20 solder were then investigated to understand the reason for the difference in thermal resistance.It was found that the microstructure with a higher content of Au-rich phase in the center of the solder and a lower content of(Au,Ni)Sn phase at the interface of the solder/heat sink resulted in lower thermal resistance.This is attributed to the lower thermal resistance of Au-rich phase and higher thermal resistance of(Au,Ni)Sn phase.
文摘High computational energy-efficiency and rapid real-timeresponse are the major concerns for applications of artificial intelligencein low-power mobile and Internet of Things deviceswith limited storage capacity. Due to the outstanding superiorityof less memory requirement, low computation overheadand negligible accuracy degradation, deep neural networkswith binary/ternary weights (BTNNs) have been widely adoptedto replace traditional full-precision neural networks.
